<template>
  <div id="home">
    <nav-bar class="home-nav"><div slot="center">购物街</div></nav-bar>
    <tab-control :titles="['流行', '新款', '精选']"
                 @tabClick="tabClick"
                 ref="tabControl1"
                 class="tab-control"
                 v-show="isTabFixed"/>
    <scroll class="content"
            ref="scroll"
            :probe-type="3"
            @scroll="contentScroll"
            :pull-up-load="true" @pullingUp="loadMore">
      <home-swiper :banners="banners" @swiperImageLoad.once="swiperImageLoad"/>
      <recommend-view :recommends="recommends"/>
      <feature-view/>
      <tab-control :titles="['流行', '新款', '精选']"
                   @tabClick="tabClick"
                   ref="tabControl2"/>
      <goods-list :goods="showGoods"/>
    </scroll>

    <back-top @click.native="backClick" v-show="isShowBack"/>
  </div>
</template>

<script>
  import HomeSwiper from "./childComps/HomeSwiper"
  import RecommendView from "./childComps/RecommendView"
  import FeatureView from "./childComps/FeatureView"

  import NavBar from "components/common/navbar/NavBar"
  import TabControl from "components/content/tabcontrol/TabControl"
  import GoodsList from "components/content/goods/GoodsList"
  import Scroll from "components/common/scroll/Scroll"

  import {getHomeMultidata, getHomeGoods} from "network/home"
  import {itemListenerMixin, backTopMixin} from "common/mixin";

  export default {
    name: "Home",
    components: {
      GoodsList,
      HomeSwiper,
      RecommendView,
      FeatureView,
      NavBar,
      TabControl,
      GoodsList,
      Scroll
    },
    mixins: [itemListenerMixin, backTopMixin],
    data() {
      return {
        banners: [],
        recommends: [],
        goods: {
          'pop': {page: 0, list: []},
          'new': {page: 0, list: []},
          'sell': {page: 0, list: []}
        },
        currentType: 'pop',
        tabOffsetTop: 0,
        isTabFixed: false,
        saveY: 0
      }
    },
    computed: {
      showGoods() {
        return this.goods[this.currentType].list
      }
    },
    activated() {
      this.$refs.scroll.scrollTo(0, this.saveY, 0)
      this.$refs.scroll.refresh()
    },
    deactivated() {
      // 1.保存Y值
      this.saveY = this.$refs.scroll.getScrollY()

      // 2.取消全局事件的监听
      this.$bus.$off('itemImageLoad', this.itemImageListener)
    },
    created() {
      //1.请求多个数据
      this.getHomeMultidata()

      //2.请求商品数据
      this.getHomeGoods('pop')
      this.getHomeGoods('new')
      this.getHomeGoods('sell')
    },
    mounted() {
    },
    methods: {
      /**
       *  事件监听相关的方法
       * */
      tabClick(index) {
        switch (index) {
          case 0:
            this.currentType = 'pop'
            break
          case 1:
            this.currentType = 'new'
            break
          case 2:
            this.currentType = 'sell'
            break
        }
        this.$refs.tabControl1.currentIndex = index
        this.$refs.tabControl2.currentIndex = index
      },
      contentScroll(position) {
        //1.判断BackTop是否显示
        this.isShowBack = (-position.y) > 1000

        //2.决定tabControl什么时候吸顶(position: fixed)
        this.isTabFixed = (-position.y) > this.tabOffsetTop
      },
      loadMore() {
        this.getHomeGoods(this.currentType)
      },
      swiperImageLoad() {
        //2.获取tabControl的OffsetTop
        //所有组件都有一个属性$sel:用于获取组件中的元素
        this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop
      },

      /**
       *  网络请求相关的方法
       * */
      getHomeMultidata() {
        getHomeMultidata().then(res => {
          this.banners = res.data.banner.list
          this.recommends = res.data.recommend.list
        }).catch(err => {
          console.log(err);
        })
      },
      getHomeGoods(type) {
        const page = this.goods[type].page +1
        getHomeGoods(type, page).then(res => {
          this.goods[type].list.push(...res.data.list)
          this.goods[type].page += 1

          //完成上拉加载更多
          this.$refs.scroll.finishPullUp()
        }).catch(err => {
          console.log(err);
        })
      }
    }
  }
</script>

<style scoped>
  #home {
    /*padding-top: 44px;*/
    height: 100vh;
    /*position: relative;*/
  }

  .home-nav {
    background-color: var(--color-tint);
    color: white;

    /*position: fixed;*/
    /*left: 0px;*/
    /*right: 0px;*/
    /*top: 0px;*/
    /*z-index: 10;*/
  }

  /*.content {*/
  /*  overflow: hidden;*/

  /*  position: absolute;*/
  /*  top: 44px;*/
  /*  bottom: 49px;*/
  /*  left: 0px;*/
  /*  right: 0px;*/
  /*}*/

  .content {
    height: calc(100% - 93px);
    overflow: hidden;
    margin-top: 0px;
  }

  .tab-control {
    position: relative;
    z-index: 9;
  }
</style>
